Automatic levelling device



lJune 18, 1957 A. LAUTENBACHER Erm. 2,795,892

AUTOMATIC LEVELLING DEVICE Filed Dec. 31, 1953 United States Patent AUTOMATC LEVELLING DEVICE Anton Lautenbacher and Johann Plank, Ingolstadt, Germany Application December 31, 1953, Serial No. 401,612

9 Claims. (Cl. 45-139) This invention relates to an automatic levelling device for taking care of uneven oors and can be applied to furniture, scaffolds, ladders, machinery, and the like. This device, when inserted into legs of furniture, pool tables, shuffle boards, machinery, etc. will take care of any unevenness in the floor by simply pressing down the one leg where adjustment is required and releasing it afterwards. A spring which is inserted in a barrel will push out a piston and then locking jaws will engage themselves, pressing against the barrel and thereby stop all further movement.

The invention does the following. For example, a table stands on an uneven floor and has the device built into two legs. All that has to be done is to press down on the side of the table where the device is inserted. As you press it down all the way, Ia spring which is mounted on the inside of the device releases the jaws and makes them ready to operate, which means after pressing all the way down you just release the pressure of the table, lift it slightly until the table is in a straight position, and the table will stay in this position and the locking device will lock itself.

In order to readjust the same table to another position, lift up on the table on the end where the device is inserted, press all the way down again, release pressure on table, lift up slightly to the position wanted and it will lock itself into position again.

Further information about the invention is shown in the drawing which shows various positions of the device.

Fig. l shows the piston completely pushed into the barrel and locking device segments as a washer.

Fig. 2 shows the levelling device according to Fig. l with the extended piston stopping on a fixed stop.

Fig. 3 is a sectional view along line 3-3 of Fig. l in the direction of the arrows.

Fig. 4 shows a view of the piston included in Figs. l and 2.

Fig. 5 shows a sectional view taken along line 5 5 of Fig. 4 in the direction of the arrows.

Figs. 6 and 7 are sectional views of another embodiment of the invention.

Referring now to the drawing, particularly to Fig. l, jaws 6 having outside corners 7 are pressed by spring 10 against the inside wall of barrel 1 and at the same time inner corners S rest against stud 9. Even pressure of jaws 6 is maintained by the pressure of spring 10 against free floating washer 11 which is bent up on the outside to guide spring 10. Between at washer 11 and jaws 6 there is a at washer 12 which permits free movement of sharp corners of the jaws when coupling movements are made. Spring 10, as well as spring 3, are guided by stationary washer 13 mounted on stud 9.

As shown in Fig. 2, spring 3 has now pressed trunk 2 out of barrel 1 to a fixed stop pin 4 which now rests against stopping block 22. The tapered corner 17 of coupling ring 14 has now pushed jaws 6 in a free moving position. Now disengaged, jaws 6 allow the trunk 2 to move freely. Flat spring 20 is resting in groove 21 and 2,795,892 Patented June 18, 1957 is holding coupling ring 14 in fixed position. Now the trunk 2 is free to move all the way out of barrel 1 up to stop pin 4 which rests on locating bracket 22, which is mounted on trunk 2.

Coupling ring 14 is free moving in the inside of barrel 1 against trunk 2. Before trunk 2 reaches its final outward movement pin 16 which is mounted -in barrel 1 with its inner end running in keyway 18 of trunk 2 pushes coupling ring 14 upward and disengages locking jaws 6. At the final movement of trunk 2 stopping pin 4 which runs in keyway 19 engages flat spring 20 in the inside groove 21 of coupling ring 14 and locks locking jaws in disengaged position. Coupling ring 14 which now disengages jaws 6 is only engaged again when trunk 2 is pushed completely into barrel 1, whereby push rod 23 which is running in keyway 18 in trunk 2 disengages coupling ring 14 which is done in the following way. Push rod 23 has a 90-degree bend on each end. The upper end is inserted into a hole of coupling ring 14 which makes a solid connection between push rod 23 and coupling ring 14 which in turn is moved along by pushing trunk 2 into barrel 1. Before trunk 2 is pushed all the way into barrel 1, push rod 23, which is shorter than coupling ring 14, is pushed against shoulder 15 of trunk 2 and disengages locking jaws 6 again. Spring 10 pushes jaws 6 back into their position according to Fig. l.

Figs. 6 and 7 differ only from Figs. l and 2 because locking jaws are now anti-friction bearing balls` which are arranged around stud 9 of trunk 2 which in turn push on the inside against stud 9 of trunk 2 in Fig. 7, and in Fig. 6 against the inside of barrel 1. Trunk 9 has a machined taper 28 on the inside. By pressing down on barrel 1 the balls will press against the taper 28 of stud 9 and thereby provide a locking device against the inside of barrel 1. The part 29 of Figs. 6 .and 7, as well as part 5 of Figs. l and 2, is a rounded off iiange.

What is claimed is:

l. An automatic levelling device for reciprocal movement comprising a barrel adapted to be inserted into a leg of a piece of furniture, a piston with a reduced stud at its inner end and an enlarged base at its outer end telescopically movable in said barrel, jaws disposed around said stud for applying pressure between said piston and an inside wall of said barrel, a spring for urging said piston out of said barrel, whereby a slight pressure is applied against said base to arrest said jaws in a predetermined position, an annular coupling slidable in said barrel adapted to apply pressure against the jaws to allow free movement of the barrel and only by pushing piston all the way back into the barrel, the coupling will release the jaws and render said jaws available for locking.

2. A device according to claim 1, wherein the coupling 14 is reciprocable in barrel 1 which rests on a shoulder of piston 2 when piston 2 is extended to a predetermined stop 16 which runs in keyway 18, which in turn brings coupling 14 to such a position that the locking jaws are disengaged.

3. A device according to claim 2, wherein coupling 14 is held in position by flat spring 20.

4. A device according to claim 3, wherein when piston 2 is completely inserted into barrel 1, coupling 14 is held against upward movement by push rod 23 which latter is stopped by pin 16 after which coupling rests again on shoulder 15 of trunk 2 which engages locking jaws again.

5. A device according to claim 4, wherein push rod 23 runs in keyway 18 in trunk 2 combined with pin 16.

6. A device in acordance with claim 5, wherein the jaws rest on trunk 2 and move upwards and sidewards, which in engaged position press with sharp outside corners 7 against inside of barrel 1 and at same time press with inside sharp corners 8 against stud 9 on piston 2.

7. A device according to claim S, wherein the jaws comprise balls 27 which are disposed around conical surface 28 of stud 9 on piston 2 which at one time rest againstrsurface 28 and at another time against inside wall of barrel 1. t Y Y 8. A deviceaccording to claim 7, wherein the jaws are under a pressure of spring 10, with a free oating washer 11 resting on said jaws, and another bearing consisting of washer 13 rigidly mounted on stud 9 of piston 2.

9. A device according to claim 8, wherein a Hat spring 20 which rests in slots 18, 19 disposed 180 apart in piston 2, which spring is held in position by retainer 22 and pin for piston 2 on outward movement.

References Cited in the le of this patent UNITED STATES PATENTS 2,176,255 Frost Oct. 17, 1939 2,204,077 Eriksson'n-; June 11, 1940 FOREIGN PATENTS 446,931 VGreat Britain May 8, 1936 841,589 France Mar. 22, 1937 

